Plotting H-R Diagrams in R

Astronomy: Exploring Space and Time

University of Arizona
Fall 2018
Created by Tony Gojanovic

What is a H-R Diagram?

The Hertzsprung-Russell diagram, or H-R diagram, is a powerful tool classifying stars in order to understand the nature of stellar evolution. More specifically, from Wikipedia, we have “The Hertzsprung–Russell diagram, abbreviated H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their stellar classifications or effective temperatures. More simply, it plots each star on a graph measuring the star’s brightness against its temperature (color). It does not map any locations of stars. The related colour–magnitude diagram (CMD) plots the apparent magnitudes of stars against their colour, usually for a cluster so that the stars are all at the same distance. The diagram was created circa 1910 by Ejnar Hertzsprung and Henry Norris Russell and represents a major step towards an understanding of stellar evolution.”

The following H-R diagrams were made using R statistical software and compiled with knitr to create an HTML document.


Hertzsprung-Russell Diagram (Yale Trigonometric Parallax Dataset)

Observational Hertzsprung–Russell diagram

The following Hertzsprung-Russell diagram is based on data found in the R statistical software library GDAData. The data is compiled from the Yale Trigonometric Parallax Dataset and can be found on the webpage of the Astronomy Department of Case Western Reserve University (see references below).

This type of H-R diagram is called an ‘observational Hertzsprung-Russell diagram’ since stars are plotted by color index (B-V) with apparent magnitude on the vertical axis. Another name for this version of the H-R diagram is ‘color magnitude diagram’ or CMD.

Note that the graph colors are not an exact match to star color, but rather just show delineations of different regions.

References

R Implementation: https://rdrr.io/cran/GDAdata/man/HRstars.html.


Simple Interactive H-R Diagram (McDonald Observatory Dataset) for Learning Project

Theoretical Hertzsprung–Russell diagram

The following interactive Hertzsprung-Russell Diagram is based on data obtained from the McDonald Observatory (see reference in this section). This data set and illustration can be used for an observational project since both right ascension and declination has been provided for the majority of stars in the diagram.

This form of the H-R diagram in which apparent magnitude and temperature is called the ‘Theoretical Hertzsprung–Russell Diagram.’ A characteristic of this form of the H–R diagram is that the temperatures are plotted from high temperature to low temperature, which aids in comparing this form of the H–R diagram with the observational form.

Note that the graph colors are not an exact match to star color, but rather just show delineations of different regions.

Spectral Types

The following table shows star names by spectral type and temperature (degrees Kelvin).

Spectral Type
star O B A F G K M
61 Cygnus A 4000
61 Cygnus B 4077
Achernar 13500
Aldebaran 3500
Alioth 9520
Altair 7700
Antares 2700
Arcturus 3900
Barnard’s Star 2600
BD +36o2147 2700
BD +43°44 A 2950
BD +43°44 B 2700
BD +59°1915A 2650
BD +59°1915B 2600
Betelgeuse 2700
Canopus 6400
Capella A 5000
Capella B 3200
Deneb 9080
Dubhe 4750
epsilon Eridani 4500
Fomalhaut 8720
HD 224014 5200
Luyten 726-8 A 2500
Luyten 726-8 B 2400
Luyten 789-6A 2500
Luyten 789-6B 2200
Merak 9520
Polaris 6400
Pollux 4100
Procyon A 6500
Procyon B 7000
Regulus 13000
Rigel A 11000
Ross 128 2600
Ross 154 2650
Ross 248 2500
Sirius A 9500
Sirius B 28000
Spica 19500
Sun 5770
Vega 9700
Wolf 359 2400
ZZ Ceti 10300
α Centauri A 5800
α Centauri B 4000
α Centauri C 2600
α Crusis A 19500
α Crusis B 16500
β Centauri 20000
β Crusis 29000
ε Indi 4000

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Star Positions by Constellation

The following table provides the star names along with apparent and absolute magnitude, temperature, constellation, right ascension and declination along with a few notes. If you’re using this to locate the stars, verify positions with a reliable star map. Not all star positions were located.

constellation star apparent absolute temp spectral_type RA Dec notes
Andromeda
Andromeda Ross 248 12.30 14.70 2500 M 23h 41m 55.0361s +44° 10′ 38.825″ Red dwarf flare star
Aquarius
Aquarius Luyten 789-6A 12.30 14.90 2500 M 22h 38m 33.73s –15° 17′ 57.3″ Red dwarf; part of a triple star system
Aquarius Luyten 789-6B 12.30 15.90 2200 M 22h 38m 33.73s –15° 17′ 57.3″ Red dwarf; part of a triple star system
Aquila
Aquila Altair 0.80 2.20 7700 A 19h 50m 46.99855s +08° 52′ 05.9563″ Type A main sequence; oblate shape
Auriga
Auriga Capella A 0.10 -0.70 5000 G 05h 16m 41.35871s +45° 59′ 52.7693″ Yellow giant; binary (part of quad system)
Auriga Capella B 0.10 9.50 3200 M 05h 16m 41.35871s +45° 59′ 52.7693″ Yellow giant; binary (part of quad system)
Bootes
Bootes Arcturus -0.10 -0.30 3900 K 14h 15m 39.7s +19° 10′ 56″ Red giant
Canis Major
Canis Major Sirius B 8.40 8.40 28000 B 06h 45m 09.0s −16° 43′ 06″ Faint white dwarf companion
Canis Major Sirius A -1.40 1.40 9500 A 06h 45m 08.917s −16° 42′ 58.02″ White main sequence star;binary
Canis Minor
Canis Minor Procyon B 10.70 13.00 7000 F 07h 39m 18.11950s +05° 13′ 29.9552″ White dwarf companion
Canis Minor Procyon A 0.40 2.70 6500 F 07h 39m 18.11950s +05° 13′ 29.9552″ Binary system star
Carina
Carina Canopus -0.60 -3.10 6400 F 06h 23m 57.10988s −52° 41′ 44.3810″ Bright white giant
Cassiopeia
Cassiopeia HD 224014 4.50 -9.50 5200 G 23h 54m 23.0s +57° 29′ 58″ Yellow hypergiant; rho cassiopeiae
Centaurus
Centaurus β Centauri 0.60 -4.10 20000 B 14h 03m 49.40535s –60° 22′ 22.9266″ Triple star system
Centaurus α Centauri A 0.00 4.40 5800 G 14h 39m 36.49400s –60° 50′ 02.3737″ Yellow main sequence
Centaurus α Centauri B 1.40 5.80 4000 K 14h 39m 35.06311s –60° 50′ 15.0992″ Orange main sequence
Centaurus α Centauri C 11.00 15.80 2600 M 14h 39m 35.06311s –60° 50′ 15.0992″ Red dwarf
Cetus
Cetus ZZ Ceti 14.10 12.30 10300 B 01h 36m 13.60s −11° 20′ 32.2″ Variable white dwarf
Cetus Luyten 726-8 A 12.60 15.40 2500 M 01h 39m 01.54s –17° 57′ 01.8″ Red dwarf flare star
Cetus Luyten 726-8 B 13.00 15.80 2400 M 01h 39m 01.54s –17° 57′ 01.8″ Companion star
Crux
Crux β Crusis 1.30 -4.00 29000 O 12h 47m 43.26877s –59° 41′ 19.5792″ Binary system star
Crux α Crusis A 0.90 -4.00 19500 B 12h 26m 35.89522s −63° 05′ 56.7343″ B-type star; multipe star system
Crux α Crusis B 0.90 -3.50 16500 B 12h 26m 35.89522s −63° 05′ 56.7343″ B-type star; multipe star system
Cygnus
Cygnus Deneb 1.30 -7.50 9080 A 20h 41m 25.9s +45° 16′ 49″ Blue white supergiant
Cygnus 61 Cygnus B 6.05 8.33 4077 K 21h 06m 55.31s +38° 44′ 31.4″ Binary k dwarf
Cygnus 61 Cygnus A 5.20 7.50 4000 K 21h 06m 53.9434s +38° 44′ 57.898″ Binary k dwarf
Eridanus
Eridanus Achernar 0.50 -1.00 13500 B 01h 37m 42.84548s –57° 14′ 12.3101″ Main sequence binary system
Eridanus epsilon Eridani 3.70 6.10 4500 K 03h 32m 55.84496s −09° 27′ 29.7312″ less than 1 billion years old
Gemini
Gemini Pollux 1.20 0.80 4100 K 07h 45m 18.94987s +28° 01′ 34.3160″ Evolved orange giant; exoplanet Pollux b
Indus
Indus ε Indi 4.70 7.00 4000 K 22h 03m 21.658s −56° 47′ 09.52″ Main sequence and two brown dwarfs; exoplanet
Leo
Leo Regulus 1.40 -0.60 13000 B 10h 08m 22.311s +11° 58′ 01.95″ Blue white; binary system
Leo Wolf 359 13.50 16.80 2400 M 10h 56m 28.99s +07° 00′ 52.0″ Red dwarf flare star
Lyra
Lyra Vega 0.00 0.50 9700 A 18h 36m 56.33635s +38° 47′ 01.2802″ Main sequence; pole star in 13, 727
Ophiuchus
Ophiuchus Barnard’s Star 9.50 13.20 2600 M 17h 57m 48.49803s +04° 41′ 36.2072″ Low mass red dwarf
Orion
Orion Rigel A 0.20 -6.80 11000 B 05h 14m 32.27210s −08° 12′ 05.8981″ Blue white supergiant; multiple star system
Orion Betelgeuse 0.50 -5.50 2700 M 05h 55m 10.30536s +07° 24′ 25.4304″ Red supergiant
Piscis austrinus
Piscis Austrinus Fomalhaut 1.20 1.60 8720 A 22h 57m 39.0465s −29° 37′ 20.050″ Tripple system star; K type main sequence
Sagittarius
Sagittarius Ross 154 10.40 13.30 2650 M 18h 49m 49.36216s –23° 50′ 10.4291″ Red dwarf flare star
Scorpius
Scorpius Antares 1.00 -4.50 2700 M 16h 29m 24.45970s −26° 25′ 55.2094″ Red supergiant
Taurus
Taurus Aldebaran 0.90 -0.20 3500 M 04h 35m 55.23907s +16° 30′ 33.4885″ Orange giant star
Ursa Major
Ursa Major Alioth 1.80 -0.20 9520 A 12h 54m 01.74959s +55° 57′ 35.3627″ A1p “peculiar”
Ursa Major Merak 2.30 0.40 9520 A 11h 01m 50.47654s +56° 22′ 56.7339″ Main sequence
Ursa Major Dubhe 1.80 -1.30 4750 K 11h 03m 43.67152s +61° 45′ 03.7249″ Giant binary
Ursa Minor
Ursa Minor Polaris 2.00 -4.10 6400 F 02h 31m 49.09s +89° 15′ 50.8″ Yellow supergiant; pole star
Ursa Minor BD +36o2147 7.50 10.50 2700 M 11h 03m 20.19400s +35° 58′ 11.5682″ Red dwarf variable
Virgo
Virgo Spica 1.00 -3.60 19500 B 13h 25m 11.579s −11° 09′ 40.75″ Blue giant; binary
Virgo Ross 128 11.10 13.50 2600 M 11h 47m 44.3974s +00° 48′ 16.395″ Red dwarf flare star
Unclassified
Sun -26.80 4.80 5770 G G type main sequence
BD +43°44 A 8.10 10.30 2950 M
BD +43°44 B 11.10 13.20 2700 M
BD +59°1915A 8.90 11.10 2650 M
BD +59°1915B 9.70 11.90 2600 M

.
References

Hemenway, Mary Kay and Brad Armosky, “H-R Diagram,” The University of Texas at Austin McDonald Observatory, 2001. Website: https://mcdonaldobservatory.org/sites/default/files/pdfs/teachers/hrd.pdf

Star right ascension, declination and notes were compiled from Wikipedia.